Hi Martin,
On 18/11/2014 2:49 PM, Martin Buchholz wrote:
Hi David,
I'm still hoping to persuade you (and others) to fix the long-standing
return-early bug in Object.wait.
Are you referring to the low level mechanics or specifically to the
nanosecond version below?
As new support for my position I offer the "at least" in JLS
https://docs.oracle.com/javase/specs/jls/se8/html/jls-17.html#jls-17.2.1
"""
If this is a timed wait, an internal action removing t from m's wait
set that occurs after at least millisecs milliseconds plusnanosecs
nanoseconds elapse since the beginning of this wait action.
"""
--- a/src/java.base/share/classes/java/lang/Object.java
+++ b/src/java.base/share/classes/java/lang/Object.java
@@ -444,16 +444,17 @@
* this exception is thrown.
*/
public final void wait(long timeout, int nanos) throws
InterruptedException {
- if (timeout < 0) {
- throw new IllegalArgumentException("timeout value is negative");
- }
+ if (nanos != 0) {
+ if (timeout < 0) {
+ throw new IllegalArgumentException
+ ("timeout value is negative");
+ }
- if (nanos < 0 || nanos > 999999) {
- throw new IllegalArgumentException(
- "nanosecond timeout value out of range");
- }
+ if (nanos < 0 || nanos > 999999) {
+ throw new IllegalArgumentException
+ ("nanosecond timeout value out of range");
+ }
- if (nanos >= 500000 || (nanos != 0 && timeout == 0)) {
timeout++;
}
That seems overly complex - after checking for valid values of timeout
and nanos you simply need:
if (nanos > 0) timeout++;
to ensure the >= requirement.
But seriously we should just deprecate this version as we're not likely
to get any underlying OS mechanisms for doing nanosecond resolution
timed blocking actions.
David
-----
On Mon, Nov 17, 2014 at 6:11 PM, David Holmes <david.hol...@oracle.com> wrote:
On 11/17/2014 2:54 PM, Martin Buchholz wrote:
Returning early is EVIL.
Yet every OS seems to allow it <sigh>
